Lepidodactylus pantai, Stubbs & Karin & Arifin & Iskandar & Arida & Reilly & Bloch & Kusnadi & Mcguire, 2017

Stubbs, Alexander L., Karin, Benjamin R., Arifin, Umilaela, Iskandar, Djoko T., Arida, Evy, Reilly, Sean B., Bloch, Luke M., Kusnadi, Agus & Mcguire, Jimmy A., 2017, A new species of Lepidodactylus (Reptilia: Squamata: Gekkonidae) from the Kei Islands, Maluku, Indonesia, Zootaxa 4350 (1), pp. 91-105 : 95-99

Lepidodactylus pantai , new species

(Figures 2,3,4)

Holotype. (Museum Zoologicum Bogoriense.Lace.14062, Field number ALS 534) An adult male collected by ALS, BRK, and UA from beachside rocks at Pasir Panjan Beach , Desa Ohoililir , Kei Kecil , Maluku, Indonesia a few hours after sunset at 5.646671° S, 132.638312° E (WGS84) on 16 October, 2011. Liver tissue is preserved in duplicate in RNA-Later at Museum Zoologicum Bogoriense ( MZB.Lace.14062) and Museum of Vertebrate Zoology ( MVZ 273691 ).

Paratypes. A series of ten additional specimens were collected at the same locality and time as the holotype ( MVZ tissue number and field number in parenthesis) : MZB.Lace.14064 (MVZ 273686; ALS 502), MZB.Lace.14065 (MVZ 273687; ALS 505), MZB.Lace.14066 (MVZ 273688; ALS 530), MZB.Lace.14067 (MVZ 273689; ALS 531), MZB.Lace.14068 (MVZ 273690; ALS 533), MVZ 273692 (ALS 501), MVZ 273693 (ALS 503), MVZ 273694 (ALS 504), MVZ 273695 (ALS 532), MVZ 273696 (ALS 535).

Diagnosis. A moderate-sized bisexual species of Lepidodactylus , SVL 36.9–40.5 (mean = 38.3) mm for five adult males and 32.0–40.5 (mean = 37.4) for five adult females, distinguished from other species by the following combination of characters: 113 rows of scales around the midbody; subdigital scansors 10–12 on toe IV, and 7–9 on toe I; terminal scansor is divided on digits II through V on both the fingers and toes; 3 scansors on 4th toe divided or deeply notched; interdigital webbing small, less than 1/5th the 4th toe length; 18–24 pores in precloacal and femoral regions of male. Tail nearly cylindrical without lateral serrations.

Description of holotype. MZB.Lace.14062 (measurements in mm, after preservation). Snout–vent length 40.57; head length 11.74; head width 7.56; head height 4.48; jaw length left/right 6.06/6.34; snout–eye length 4.54; naris–eye length 3.13; naris circular, approximately 0.4×0.5; orbit diameter 2.46; eye–ear length 3.38; snout width 1.78; ear opening length×width 0.62×0.41; interorbital width 4.00; snout–forelimb length 14.13; axilla–groin distance 20.05; length of hind limb 15.13 (75.5 % of axilla–groin distance); length of forelimb 10.95; crus length 6.41; tail length 24 (entire); tail width 4.34; tail depth 3.88.

Snout tapered, rounded at tip; three scales touching rostral between left and right nares; supranasals separated by three scales in contact with rostral; rostral entering nares, broader than high, 2.05×0.89 (width about 2.3 times height); no rostral cleft; nares bordered by five scales: three nasals, one rostral, and one supralabial; 34–35 interorbital scales; 11 left and 11 right supralabials, 10th below center of eye; 10 left and 10 right infralabials; mental scale distinct, triangular, its anterior width nearly equal to midline length (0.69×.0.72); Mental is bordered posteriorly by two enlarged primary postmentals, each in contact with the first infralabial.

Body slightly depressed; 113 rows of scales (average of 3 counts: 109, 114, 116) around midbody, grading into granular scales on lower lateral surfaces; dorsal and lateral scales granular, without enlarged tubercles; ventral scales almost flat, hexagonal, and 2–3 times larger than dorsal scales; limbs well developed; digits moderately dilated, undersurface ( Fig. 3 ) bearing left/right scansors as follow: fingers— I 9 /9, II 9/ 10, III 12 / 12, IV 13 / 13, V 9 / 9; toes—I 10/(not intact), II 11/ 11, III 14 / 14, IV 12 / 12, V 9 /9; distal three scansors, including the terminal one, divided on all digits except the first on fingers and toes; first digit with complete terminal and two divided subterminal scansors; all digits except first with 3 undivided or deeply notched scansors, including the terminal; all digits except first clawed; compressed claw-bearing phalanges arising from distal margin of the dilated part and extending only a short distance beyond; slight webbing 1/6th of the length of the 4th toe; digits elongate and slender, toe pads slightly enlarged.

Twenty five enlarged precloacal and femoral scales; two post-cloacal spurs on each side of vent; tail entire, subcylindrical throughout length, gradually tapering to a blunt tip; lateral margins without spines or skin flanges; tail constricted at base posterior to vent; scales on tail annulate, squarish or rectangular, ventral scales about twice as large as dorsal scales; base of tail distinctly swollen by hemipenes; hemipenes everted, forked with small, flared scales on the midbody of each forked end, transitioning into even smaller distal scales about half the size.

Color in preservative. Color of holotype after about three years in ethanol is similar to coloration in life ( Fig. 2 ). Overall dorsal coloration is pale grey with some lateral streaks of darker pigment. Two pairs of dark spots are clearly visible on the dorsal surface of tail. Venter of body pale cream in color with no distinct pigmentation. Ventral surface of tail slightly darker posteriorly. Slight dark spotting on the dorsal surface of the head. A brown orbital stripe extends from the nostril to the anterior insertion of the forelimb. Three elongated spots on dorsal surface of body between the insertions of the forelimbs.

Variation. The type series varies in SVL (20.6–40.5; n=11), number of precloacal pores in males (17–25; n=5), number of scansors on Toe IV (10–12, n=11), number of lamellae on Toe I (7–9, n=11), number of supralabials (11–14, n =11), number of infralabials (9–11, n=11), head width as a proportion of SVL (18–21%, n=11), and number of scale rows around the midbody (108–127, n=11). Nearly all specimens have two cloacal spurs, however two specimens have an additional cloacal spur on one side of the body. All specimens have three divided terminal scansors. Both males and females of the type series possess enlarged, pale-white, endolymphatic sacs, which are more pronounced in females.

Coloration is similar among the type series ( Fig. 4 ), however patterning is somewhat variable. Some specimens possess distinct dark chevron patterning along the dorsal surface of the body. All members of the type series have three elongate dark spots on the dorsal surface of the body between the insertions of the forelimbs. The lateral surfaces of some specimens have darker brown pigmentation, with a pale cream dorsal band running from the temporal region posterior to the base of the tail. The orbital stripe is variable in conspicuousness, though all specimens possess it to some degree.

Coloration in life ( Fig. 2 ) is very similar to that in preservative ( Fig. 4 ), however some of the darker regions also contain reddish pigment that has been lost in preservation. As with many geckos, these individuals change their level of pigmentation with time of day and light environment. Figure 2 shows a color photograph of this species in situ (specimen uncollected) from the type locality taken on a more recent expedition in 2014.

Distribution. The type series are all from Kei Kecil, however we recently collected another series of specimens from Kur Island (~ 80 km to the northwest) that appears morphologically similar, however further analysis is needed to determine the level of divergence between these two populations. Our phylogeny also indicates that specimens from Palau are remarkably similar genetically but we refrain from assigning members of that population to this species at present time.

Natural history. We have experience with this species only on two islands, Kei Kecil and Kur. Specimens were associated with exposed intertidal limestone rock formations in both cases (see Fig. 1 ; habitat).

All specimens were found at night on beachside limestone rocks ( Fig. 1 ) or in mangroves within meters of the high tide line. Despite nearly a month of intensive nightly collecting effort (targeting geckos) on Kei Kecil we were unable to find this species in the adjacent disturbed forest. While on Kei Kecil, we resided in a small house approximately 30 meters from the high tide line and collected many other species of geckos on a small wooden shed but L. pantai sp. nov. were never encountered on this structure. This species was discovered accidentally at the end of our stay on Kei Kecil while surveying for laticaudine sea snakes in the intertidal zone. We think this shows the potential importance of sampling intertidal areas at night, something rarely done by herpetologists. All 11 specimens in the type series were collected over the span of less than one hour, and subsequent visits to Kei Kecil confirmed that this species is locally abundant, occasionally in densities of up to 1 individual per square meter. Terrestrial hermit crabs and marine isopods were also abundant on the same rocks and we believe this resource subsidy of food from the marine environment likely contribute to the locally high densities observed in this species.

On Kur island, only 80 km northwest of Kei Kecil, morphologically similar geckos were also found in association with the intertidal zone and limestone rocks, but they were also numerous in a small patch of mangroves. The roots of these mangroves were submerged during high tide, but specimens were found at an even higher density on mangroves than on exposed limestone rocks (though the small mangroves were themselves growing among limestone rocks). When associated with mangroves, this species appeared to be very abundant close to the water, but trees slightly above the high-tide line were inhabited almost exclusively by another undescribed species of Lepidodactylus and members of the gekkonid genus Cyrtodactylus .

Etymology. The species epithet, pantai , is the word for beach in the Indonesian national language (Bahasa Indonesia). It reflects the habitat in which the new species was discovered—a seemingly obligate association with the seashore. All specimens were found within 2 m of the high tide line. We suggest “Beach Scaly-toed Gecko” as the English common name for this species.

Comparisons. The new species is the only member of the genus with divided terminal 4th toe scansors and a cylindrical tail without lateral serrations. Brown & Parker (1977) divided the genus Lepidodactylus into three groups but L. pantai sp. nov. differs from all of the previously recognized groups in having divided terminal scansors on toes 2–5 and a tail that is fully cylindrical without any fringes or compression.

The presence of divided scansors distinguishes L. pantai sp. nov. from all Group I Lepidodactylus ( L. listeri , L. magnus , L. manni , L. mutahi , L. oorti , L. orientalis , L. pumilus , L. browni , L. euaensis , and L. flaviocularis ), which have no divided scansors ( Brown & Parker 1977). The presence of divided terminal scansors on toe IV distinguishes L. pantai sp. nov. from all Group II Lepidodactylus which have undivided terminal scansors ( L. gardeneri , L. guppyi , L.novaeguineae , L. pulcher , L. shebae , L. buleli , L. intermedius , L. lombocensis , L. paurolepis , L. vanatuensis , L. oligoporus , L. tepukapili , and L. ranauensis ). The presence of a cylindrical tail without lateral serrations distinguishes L. pantai sp. nov. from Group III Lepidodactylus that have depressed tails with lateral serrations ( L. moestus , L. lugubris , L. woodfordi , L. yami , L. aureolineatus , L. balioburius , L. christiani , L. herrei , and L. planicaudus ). Lateral serrations are sometimes absent on L. yami ( Ota 1987) , but L. pantai sp. nov. can be further distinguished from L. yami by the number of scansors on Toe IV (10–12 in L. pantai sp. nov. versus 13–15 in L. yami ) and the number of midbody scale rows (108–127 in L. pantai sp. nov. versus 145–148 in L. yami ).

Figures

FIGURE 1. Habitat of L. pantai sp. nov. at the type locality on Kei Kecil. Specimens were found exclusively in association with limestone rocks in the intertidal zone.

FIGURE 2. Photo in life of Lepidodacylus pantai sp. nov. from the type locality. (Photo by LMB, 2014).

FIGURE 3. Plantar view of the right foot of the holotype (MZB. Lace. 14069). Note the 3 divided terminal scansors on toes 1 - 4.

FIGURE 4. Dorsal color pattern variation in the type series. Specimen tags overlaid with museum accession numbers.